This cleans up the Alacritty scripts a bit by removing some of them
which are not recommended to be used anymore and switching from the
official FlameGraph tool to the more specialized Rust FlameGraph
implementation.
This includes some changes to the scripts `README.md` to provide
some more information on the different Alacritty scripts.
A new script for testing the 24 bit support of Alacritty has been
added with the `24-bit-color.sh` name. This should help with
troubleshooting truecolor support issues.
Since `perf` is a standard tool which is available in the official
repositories for most distributions, it doesn't make much sense to
provide an installation script specifically for Ubuntu. As a result of
this, the script has been removed.